The invention relates to a method for setting up a protective sealing layer in a landfill basin for industrial and mining slurries and a geotextile protective tube mat for carrying out the method.
Slurry-like waste occurs in industrial processes, in particular in the mining industry. In the mining industry, these are, in particular, residues from the treatment of ores, which are present in the form of slurries and are referred to as tailing. These slurries are collected in so-called slurry ponds and stored permanently, whereby an absolute tightness of a sealing layer covering the bottom is required and this over a very long period, since it is usually a repository for the waste, thus remaining permanently in the slurry ponds. The production of a completely tight and against the substances contained in the slurries chemically resistant sealing level is basically possible according to the prior art. However, the bottom sealing layer, usually consisting of a plastic sealing strip with additional layers is endangered by the effects of heat and UV radiation as well as due to mechanical damage.
The mechanical damage can result from driving and walking on the sealing level. The application of a protection layer against UV and heat made of sand, soil or mixtures containing concrete is possible, but requires large machinery considering the large dimensions of the slurry ponds and the enclosing embankments to transport and distribute the material. The bottom sealing layer is often damaged by driving on the embankments, so that leaks can occur even with the use of multi-layer sealing strips, resulting in a significant environmental hazard.
To improve the leak tightness, it is also known to incorporate so-called GCL mats (Geosynthetic Clay Liner) containing a bentonite mixture that swells under the action of water to form a tight layer. However, this would require providing a uniform surface pressure on the mat filled with bentonite, otherwise there is locally different swelling and a tearing apart of the bentonite layer.